The present invention relates generally to analysis of integrated circuit (IC) devices and, more particularly, to defect detecting of shorts in IC dies.
The semiconductor industry has recently experienced technological advances that have permitted dramatic increases in circuit density and complexity, and equally dramatic decreases in power consumption and package sizes. Present semiconductor technology now permits single-chip microprocessors with many millions of transistors, operating at speeds of hundreds of millions of instructions per second to be packaged in relatively small, air-cooled semiconductor device packages. These technological advances have fueled an increased demand for semiconductor devices and products that employ semiconductor devices. A byproduct of this increased demand has been a need to manufacture semiconductor devices in an efficient manner as considerations including device speed, reliability and affordability become increasingly important. In order to meet these and other needs, analyzing dies for functional defects has become increasingly valuable.
One type of defect that presents challenges to semiconductor device design and analysis is a defect that includes a short circuit. Circuit elements such as source/drain elements, gates, interconnects and various other elements can exhibit shorts between one another as a result of design and/or manufacturing problems. These shorts are often difficult to detect and to pinpoint. For example, a silicide short between a gate and a source/drain region is difficult to distinguish from a short resulting from a gate oxide defect. Identifying the nature of the short often requires that the defect be visually detected. At times, such analysis even requires that the die be destroyed or otherwise damaged, making it difficult or impossible to perform further analysis on the die, or to use the die in any capacity.
The difficulty in differentiating between non-oxide and oxide-related shorts makes analysis and design of semiconductor devices difficult and thus is a hindrance to the advancement of semiconductors and related technologies.
The present invention is directed to the detection and differentiation of defects in semiconductor devices, and is exemplified in a number of implementations and applications, some of which are summarized below.
According to an example embodiment of the present invention, a semiconductor die having gate, source/drain and well regions is analyzed. The die is susceptible to a short attributable to at least one of a gate oxide short and a source/drain silicide short. The die is stimulated, and an electrical response of the die to the stimulation is detected. The response includes an electrical characteristic of the die that exhibits a first response if the short is a gate oxide short, and exhibits a second response if the short is a non-oxide short. The stimulation may, for example, be selected to cause a particular failure or short in the device. When the detected response exhibits the first response, a gate oxide short is detected, and when the detected response exhibits the second response, a non-oxide short is detected. In this manner, the detection and identification of failures in semiconductor devices is improved because the electrical characteristic provides a differentiation between oxide and non-oxide shorts, addressing challenges including those discussed in the Background hereinabove.
According to another example embodiment of the present invention, a system is adapted for analyzing a semiconductor die having gate, source/drain and well regions. The die is susceptible to an electrical short attributable to at least one of a gate oxide short and a non-oxide short. The system includes an electrical testing arrangement adapted to stimulate the die. A response from the stimulated die is detected by a test circuit adapted to detect a response including an electrical characteristic that exhibits a first response if the short is a gate oxide short and exhibits a second response if the short is a non-oxide short. A comparison device is adapted to detect whether or not the short is a gate oxide short in response to the electrical characteristic.
The above summary of the present invention is not intended to describe each illustrated embodiment or every implementation of the present invention. The figures and detailed description that follow more particularly exemplify these embodiments.